Riscv GCC 4.9.2不能编译linux 3.14.29

Question

当我使用riscv gcc (verison4.9.2)编译linux(3.14.29版)时，我遇到了一些错误，看起来gcc无法识别某些操作码，我如何解决这个问题？把gcc改为4.6版？谢谢

root@riscv-VirtualBox:/home/riscv/riscv/linux-3.14.29# make ARCH=riscv
scripts/kconfig/conf --silentoldconfig Kconfig
  ......
/home/riscv/riscv/linux-3.14.29/arch/riscv/include/asm/irqflags.h: Assembler messages:
/home/riscv/riscv/linux-3.14.29/arch/riscv/include/asm/irqflags.h:22: Error: Instruction csrc requires absolute expression
/home/riscv/riscv/linux-3.14.29/arch/riscv/include/asm/irqflags.h:22: Error: Instruction csrc requires absolute expression
/home/riscv/riscv/linux-3.14.29/arch/riscv/include/asm/irqflags.h:10: Error: Instruction csrr requires absolute expression
/home/riscv/riscv/linux-3.14.29/arch/riscv/include/asm/irqflags.h:22: Error: Instruction csrc requires absolute expression
/home/riscv/riscv/linux-3.14.29/arch/riscv/include/asm/irqflags.h:22: Error: Instruction csrc requires absolute expression
/home/riscv/riscv/linux-3.14.29/arch/riscv/include/asm/irqflags.h:10: Error: Instruction csrr requires absolute expression
/home/riscv/riscv/linux-3.14.29/arch/riscv/include/asm/irqflags.h:16: Error: Instruction csrs requires absolute expression
/home/riscv/riscv/linux-3.14.29/arch/riscv/include/asm/irqflags.h:16: Error: Instruction csrs requires absolute expression
/home/riscv/riscv/linux-3.14.29/arch/riscv/include/asm/irqflags.h:10: Error: Instruction csrr requires absolute expression
/home/riscv/riscv/linux-3.14.29/arch/riscv/include/asm/irqflags.h:16: Error: Instruction csrs requires absolute expression
/home/riscv/riscv/linux-3.14.29/arch/riscv/include/asm/irqflags.h:16: Error: Instruction csrs requires absolute expression
make[1]: *** [init/main.o] Error 1
make: *** [init] Error 2

root@riscv-VirtualBox:/home/riscv/riscv/linux-3.14.29# riscv64-unknown-elf-gcc --version
riscv64-unknown-elf-gcc (GCC) 4.9.2
Copyright (C) 2014 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Answer 1

存储库中存在不匹配(这可能不是您的错)。您可以尝试检查"new_privileged_isa“分支，但问题是RISC-V特权规范(截至2015年4月30日)仍在变化中，我们不能保证分支机构的负责人都能一起工作。

Answer 2

Chris，我使用以下方法安装riscv-tools：

git clone https://github.com/riscv/riscv-tools.git
git submodule update --init --recursive
./build.sh

并使用以下方法获取linux源代码：

 curl https://www.kernel.org/pub/linux/kernel/v3.x/linux-3.14.29.tar.xz | tar -xJ 
cd linux-3.14.29 
git init 
git remote add origin https://github.com/riscv/riscv-linux.git 
git fetch 
git checkout -f -t origin/master